B♭ dominant 7th arpeggio on bass

B♭ · D · F · A♭

The course explains what this page shows in Lesson 13 · Sevenths.

The notes

  1. B♭1
  2. D3
  3. F5
  4. A♭♭7

The B♭ dominant 7th arpeggio is B♭, D, F, A♭.

You may also see it called 1 3 5 ♭7.

On the staff

B♭CDE♭FGA♭B♭

On a bass staff, the B♭ dominant 7th arpeggio is written B♭ D F A♭.

The solid notes are the B♭ dominant 7th arpeggio. The pale notes are the rest of B♭ mixolydian, the larger scale it is carved out of, so you can see which notes it leaves out.

Why the B♭ dominant 7th arpeggio has these flats

  1. B♭1
  2. 4
  3. D3
  4. T+S
  5. F5
  6. T+S
  7. A♭♭7
  8. T
  9. B♭8

A scale is a pattern of steps, and this one is 4 T+S T+S T: 4, a tone and a half, a tone and a half, and so on. T stands for a tone, which is two semitones. T+S stands for a tone and a half, which is three semitones. 4 stands for a step of four semitones. The pattern is what gives B♭ dominant 7th its sound, and it stays the same whichever note you start on.

This scale has only four notes, so it does not use every letter. It is built on B♭ mixolydian, and the notes it shares are spelled the same way as they are there.

The pattern still does not fit the plain letters. If you walk the pattern up from B♭, one letter cannot keep up:

  • A♭ — the flat seventh. The pattern needs a tone and a half from F, but F to A is only 4, so A has to fall to A♭.

That accidental was not a choice. Once you pick the note to start on, the pattern decides the rest, and a key signature is a record of the result.

The B♭ dominant 7th arpeggio is written with B♭ and A♭. B♭ has its accidental because that is the key, and the other note needs one because the 4 T+S T+S T pattern of steps cannot be spelled from B♭ with plain letters.

The pattern of steps is the part of a scale that never changes. The letter names take sharps or flats to fit that pattern, and a key signature is a record of those sharps or flats.

On the piano

2C3DE5F6GAB2C3DE5F6GAB2C3DE5F6GAB2CC♯4E♭F♯♭7A♭1B♭C♯4E♭F♯♭7A♭1B♭C♯4E♭F♯♭7A♭1B♭C1C2C3C4

The keyboard shows the same four notes as a shape you can see. The coloured keys are the B♭ dominant 7th arpeggio, the pale keys are the rest of B♭ mixolydian, and you can click any key to hear it.

B♭ dominant 7th arpeggio on the whole neck

EADG123456789101112131415F5A♭♭7B♭1D3F5B♭1D3F5A♭♭7B♭1D3F5A♭♭7B♭1D3F5A♭♭7B♭1D3F5A♭♭7B♭1

29 notes of the B♭ dominant 7th arpeggio are marked across four strings.

This is every place the notes of the B♭ dominant 7th arpeggio fall on the bass, with each note's name and its scale degree. The roots are marked so you can find your bearings.

Position by position

Position 1 — starts on the 5
EADG1234565♭7135♭71
Position 2 — starts on the ♭7
EADG456789♭7135♭713
Position 3 — starts on the 1
EADG67891011135♭7135
Position 4 — starts on the 3
EADG10111213141535♭7135♭7

The B♭ dominant 7th arpeggio has four playable positions, at frets 1–5, 4–8, 6–10 and 10–14.

Each shape starts on a different degree of the scale and fits inside five frets, so your hand can play all of it without moving.

One climb up the neck

EADG678910111213141516135♭7135♭71TAB6108111312151315

The climb runs from fret 6 to fret 15 and plays nine notes.

This is one path from the lowest root to the top of the neck, and it plays each note once, never on two strings. It takes a different number of notes on different strings. The widest stretch on any one string is five frets.